Jul 24, 2012 5:24 PM

This is another field guide problem. Here's a nice Pearly Heath (Coenonympha arcania) that I photographed (near Madrid) this morning and it matches the description in my guide very well (FW uns orange with a brown border and small apical eye-spot; Hw uns brown with a broad white or cream-coloured postdiscal band; One of the orange-ringed eye-spots situation on the inner side of the white stripe).

Identification clear, no? But here's two more photographed this morning. The first just about has an apical eye spot (look very carefully and you'll see the vestiges of the spot) but the second has no trace of it.

So is this last specimen Coenonympha arcania and the guide is out-of-date, or is it a new sub-species?

Thanks. When I wrote this my only field guide was Butterflies of Britain and Europe, Haahtela et al. I now also have the Collins Butterfly Guide. Curiously, neither of them mention ssp huebneri. So I am still left wondering why such "authoritative" guides should leave out a subspecies. Does this mean the ssp has only recently been recognised, the guides were always incorrect or that the ssp has not been officially recognised. It's all very frustrating.

Do you know if there is a specification of huebneri anywhere? I ask because I've now studied the link you supplied and I came to a different conclusion from you. If you look closely at the only photo of huebneri you will see there is a vestigial spot on the forewing

(NB if you click on the image, as I did, it is displayed in mirror form for some reason.) On the other hand, when I look closely at the very first image of arcania I cannot find any trace of a spot. Hence my confusion. If the missing spot is not the mark of huebneri, what is?

I was presuming the first photo simply had not been upated in respect of being the ssp. (none of the images are captioned as ssp. arcania, ie. being ofthe type ssp.). I could be wrong; we don't know the differentiating factor(s) for ssp. huebneri.

However, I would presume C. a. huebneri is a new combination for Coenonympha huebneri Oberthür 1910

1) Yes, I agree there is a vestigial eye-spot on the first image of arcania. My PC has two screens and it may be that they have different contrast settings and I didn't see this before.

2) I have found Beccaloni G on the NHM website with contact details and I have sent him a request to look at this thread and offer whatever clarification he can. So personally I will await his response.

Bear in mind we are into territory where there are splitters and lumpers; experts may have differing opinions; one may choose to consider huebneri a subspecies while the other may look on it as merely representing part of the range of variation of the species (arcania).

From the comments of Jurgen at lepiforum.de, he appears to be a splitter - recognizing it as a subspecies.

Beccaloni G on the NHM website appears to be a lumper, hence huebneri being a synonym for arcania there.

Hopefully one/both of them (or somebody else) can elucidate the differentiating factor(s) [I am still not sure how to interpret that translation]. Then we/you can decide:

George Beccaloni replied to meot the effect that he no longer works on Lepidoptera but he did get a response form a colleage Dr Ian Kitching:

"Can't really help. The index card has no annotations and just states that huebneri is a junior synonym of arcania. Neither Markko Savela's website nor Fauna Europaea mention huebneri or Higgins & Riley's book (because they all consider it infrasubspecific?). Looking at the original description, there is a suggestion that it may be an unavailable name proposed for an individual variety but the OD would need careful translation and then even more careful interpretation under the Code given it is one of those pre-1931 "varieties". I guess someone somewhere (Germany?) may have raised it to subspecies status but I have no idea who or why. It is still treated as a JSS of arcania in the current version of the database but then we have had no reason to change it.

Sorry I can't help further."

So that leaves us where? The middle image may be of a sub-species huebneri or this may just be a variation within arcania. Is that also true of my third image, the one lacking even a vestigial spot? My Field guide is quite specific about an apical eye-spot. When I look in the place where the sopt should be I can see a mark, but it is no different from the many other marks that add a darker tone to the outer margin of the wing. Should I register williamskeyi as a subspecies of arcania? :-)

Yes - it is all a bit vague. Such is life; we don't always get what we'd like.

Personally, I would stick with just C. arcania, and look upon the description in your field guide as being a little simplified, in that it might not account for the end-point of the spectrum of eye-spot distinctiveness (where it vanishes).